Field of the Various Embodiments
The various embodiments relate generally to audio systems and, more specifically, to redistributing gain to reduce near field noise in head-worn audio systems.
Description of the Related Art
Many head-worn audio systems acquire sound from surrounding environments via integrated microphones and then deliver associated sound to the users of such systems via integrated speakers. Well-known examples of such head-worn audio systems include wired and wireless hear-through headphones, binaural (i.e., targeting both ears of a user) hearing aids, and the like. With these types of head-worn audio systems, undesired sound may be received by one of the microphones from a source that is located relatively close (e.g., two wavelengths) to the microphone and then transmitted to the user via the integrated speaker associated with the microphone. Such undesired sound is referred to as “near field noise,” and this type of noise can substantially degrade the quality of the listening experience. Examples of near field noise include acoustic feedback, noise associated with the microphone itself, wind noise, and chewing noise, to name a few.
In an attempt to improve the quality of the listening experience, some head-worn audio systems include fitted inserts that attempt to position the speakers more tightly within the ears of a user. For example, some earphones may include ear buds that are designed to fit inside the pinna regions of the user's ears, and some hearing aids are custom-fit for each ear of the user. When fitted inserts are worn by a user, each integrated speaker creates a sound chamber relative to one of the ears of the user that reduces the amount of sound that is leaked outside the ear during operation as well as the amount near field noise attributable to that leaked sound.
One limitation of the conventional designs noted above is that those designs still suffer from the effects of near field noise. For example, as indicated above, fitted inserts reduce, but do not necessarily eliminate, near field noise because the sound that travels through the fitted inserts within the ears as well as leaked sound can cause acoustic feedback. Many of the other conventional designs discussed above do not include fitted inserts, but, instead, include open-back earphones. These types of earphones provide acoustic transparency that enable the user to hear sounds from the outside environment during operation, but allow a relatively large amount of sound to be leaked outside the ears during operation. Consequently, users oftentimes experience degraded listening experiences attributable to near field noise with such designs.
As the foregoing illustrates, more effective techniques for delivering sound via head-worn audio systems would be useful.